The present invention relates to a linear guide device, comprising a guide rail having a longitudinal axis, at least one guide carriage guided on the guide rail in the direction of the longitudinal axis by means of at least one rolling member loop circulating in a circulation space of the guide carriage, said rolling member loop including a bearing row of rolling members in simultaneous engagement with a bearing track of the guide rail and a bearing track of the guide carriage, a further returning row of rolling members and two arcuate rows of rolling members, said guide carriage comprising a carriage main body in the longitudinal region of the bearing row of rolling members and end units at the axially spaced ends of the carriage main body, reversing guides for the arcuate rows of rolling members being formed at least partly on the end units, a lubricant demand existing on at least a part of the roll surfaces of the linear guide device and a lubricant path system being provided in the guide carriage for satisfying said lubricant demand, said lubricant path system extending from a lubricant supply space of the guide carriage to roll surfaces, said lubricant path system being accommodated at least in part in a boundary region between at least one end unit and the carriage main body.
Such linear guide devices are known from EP 0 211 243 A2, U.S. Pat. No. 4,850,720, DE 42 10 299 C2 and DE 44 24 795 A1. In these known embodiments, the lubricant path system comprises in its end portion close to the rolling members a lubricant channel within a radially inner reversing member of a reversing guide. This lubricant channel terminates into a reversing surface of the reversing member and thus into the circulation space of the rolling members.
According to U.S. Pat. No. 4,850,720, the outlet opening of the lubricant channel extending within the radially inner reversing member is formed as a throttle valve in the form of a narrow-sized bore which extends from the lubricant channel in radial direction to the radially inner reversing surface of the reversing member.
According to DE 42 10 299 C2, at the outlet zone of the lubricant channel into the radially inner reversing surface relief pressure valves are provided which open as the lubricant pressure is increased but prevent lubricant from flowing off under the influence of gravity. This embodiment is said to be especially suited if low-viscosity oil is used as the lubricant. According to this embodiment, the relief pressure valves are provided directly at the outlet into the circulation space of the rolling members, i.e. at the radially inner reversing surface of the reversing member.
According to DE 44 24 795 A1 the lubricant oil flows out into the circulation space of the rolling members through outlet channels of the radially inner reversing member, which outlet channels terminate into the radially inner reversing surface of the reversing member. These outlet channels begin within a common throttle chamber which receives a foam material strip. Upon transmission of a lubricant oil pulse, the oil penetrates the open-cell foam material which serves as a throttle means. The foam material has no contact with the rolling members. After having penetrated the foam material, the lubricant oil flows through the outlet channels from the throttle chamber into the circulation space, as a consequence of a pressure pulse. The foam material strip prevents oil from flowing out into the circulation space if no pressure pulse has been applied. With this embodiment, it is not excluded that, caused by one or a plurality of consecutive pressure pulses, too much oil gets into the circulation space. There is the that lubricant oil might flow out into the ambient if the circulation space has not been made oil-tight. On the other hand, there will also be the danger that too little lubricant oil is availabe for the circulating rolling members if the lubricant oil contained in the circulation space has been consumed prematurely between two consecutive pressure pulses. The technical problem underlying the present invention is to take care in case of the use of lubricant oil that sufficient lubricant oil is always and over a long period of time available in the circulation space and to simultaneously take care that no lubricant oil quantities beyond the respective lubricant demand get into and possibly out of the circulation space.